I'd still be seriously concerned about how few eyeballs they get with regards to security---Google has entire fleets of machines dedicated to fuzzing every line of Chromium code and both Chrome and Firefox use advanced sandboxing to make it so that a single exploit in the JavaScript engine wouldn't be able to result in user-level remote code execution. I'm sure they're both probably fine (if nothing else from security by obscurity) but modern browsers are complicated pieces of software that require a lot of engineering to keep secure.

GNOME Web is based on WebKit, while Falkon has migrated away from QtWebKit to QtWebEngine, which is Chromium based.

It's slightly ironic for KDE, as Blink is a fork of WebKit, which itself is a fork of KHTML, which was originally the KDE HTML renderer.

Full circle!

KDE also has Konqueror, which now allows you to use either KHTML or WebKit as the rendering engine. KHTML works fine on simple sites like Hacker News nowadays but chokes on newer ones often.